Apparatus for guiding strip stock



March 8, 1966 K. E. SENGEL 3,239,613

APPARATUS FOR GUIDING STRIP STOCK Filed Jan. 29, 1965 K J M 25/ 9 a 10/l M Z 4 O L/ 1a 7 73 lNVENToR KURT E. SENGEL RTTORNEYS United StatesPatent 3,239,618 APPARATUS FOR GUIDING STRIP STOCK Kurt E. Sengel,Friedrichshafen, Germany, assignor to Driam Socit Anonyme, Vaduz,Liechtenstein Filed Jan. 29, 1963, Ser. No. 254,616 Claims priority,application Germany, Feb. 2, 1962,

38,073 7 Claims. (Cl. ZOO-61.18)

The present invention relates to an apparatus for guiding strip stockand the like. 1

In numerous processes in which sheet materials in the form of strips,bands, or sheets have to be fed and accurately guided in theirlongitudinal direction so that either their central axes or one of theiredges will remain in their prescribed positions, considerabledifficulties occur when the strip band or sheet varies in width whichhappens very frequently as the result of inaccuracies in manufacture.Although these difficulties may be reduced to some extent by a specialedge trimming operation, often it is even then difficult to avoid themcompletely unless a considerable amount of material is cut off which isthus wasted entirely.

When speaking hereafter only of strips this term is intended to includegenerally any sheet material in the form of strips, bands, sheets, orthe like.

The apparatus for guiding such strips generally consist of rollers orsliding jaws which are usually adjustable in a direction transverse tothe axis of the strip in accordance with the nominal width of the stripby means of screw spindles or the like. It is a well-known fact that, ifthe strip which is being fed varies in width, there is eitherconsiderable play between these guiding means and the edges of the stripor the guiding means will exe'r't too great a pressure upon these edges.

Since both of these occurrences should be avoided as much as possible,the guiding means for one or both edges of the strip are usuallyresiliently mounted. The result is then either a varying pressure uponthe edges of the strip, for example, if the guiding means are acted uponby springs, or a constant pressure, for example, if

the guiding means are acted upon by hydraulic or pneumatic cylinders.This pressure upon the edges of the strip may also be adjusted inaccordance with the dimensions and the type of material of the strip.

All of these resilient guiding means have the disadvantage that thepressure upon the edges of the strip :must be exerted continuouslysince, if they operate, for example, with springs of an insufiicientstrength and the strip decreases in width, they are no longer able toshift the strip laterally and thus fail to carry out their guidingfunction.

The known guiding means therefore do not permit untrimmed strips whichhave the usual manufacturing tolerances amounting, for example, toapproximately 1% of the nominal width of the strip, to be guided in sucha manner that there will always be a constant light guiding pressureupon the edges of the strip and that a sufiicient force will also beexerted upon the strip so that, if it should tend to run in a slightlyoblique direction, it will be maintained in or returned to the desiredposition.

It is an object of the present invention to provide suitable guidingmeans which exert a relatively :low pressure upon the edges of the stripas long as the strip is of a normal condition, that is, as long as thewidth of the strip remains the same and also as long as these guidingmeans are in engagement with both edges of the strip. If, however, onlyone or both edges of the strip disengage from the guiding means or ifthe pressure of the latter upon one or both edges of the strip increasesbeyond a preset limit, the invention provides that the guiding means aremoved automatically in one or the other direction in such a manner thatthe pressures which are exerted upon the edges of the strip will remainwithin certain adjustable limits so that any damage to the edges of thestrip or to the guiding means'will be prevented.

According to the invention, this object is attained by providing one ormore pairs of guiding means which are movable perpendicularly to theaxis of the strip and wherein those of each pair are disposed directlyopposite to each other at both edges of the strip. These guiding meanspossess the following features:

(1) Each of these guiding means comprises a guiding element and asupporting slide member therefor which is capable of reciprocatingwithin a normally stationary slide carriage or housing for a relativelyshort distance between two fixed stops in a direction transverse to theedges of the strip, and this distance is adjustable, although it isalways considerably smaller than the tolerances in the width of thestrip which are normally to be expected.

(2) Each guiding element is pressed against the edge of the strip oragainst the respective stop by a relatively weak spring which only needsto be strong enough to compensate for the friction caused by this guideelement and the other elements within each carriage.

(3) In addition to this weak spring, preferably a coil spring, a hardspring, for example, a cup spring, is provided in such a manner that thedistance of travel of both springs together is divided into a longerpart with a practically constant but relatively weak spring pressure ofthe coil spring and a smaller part with a strongly increasing springpressure of the cup spring.

(4) The normally stationary carriages for each pair of guiding elementsare adjustable relative to each other, for example, by an electric motorand a screw spindle with right and left-hand threads, and such anadjustment may be carried out manually by the operation of a pushbuttonfor the purpose of adjusting the guiding elements to the normal width ofthe strip and also automatically by means of a limit switch with whicheach slide carriage is equipped and which is actuated by the stroke ofthe guide element. Each limit switch has, for example, three switchingpositions so that both limit switches together are capable of attainingnine possible switching combinations for controlling the electric motor.Two of these nine combinations are employed for starting the motor inits two different directions of rotation, while all of the other sevenswitching positions will either cause the motor to stop or not permit itto start.

(5 The limit switch which is installed in each carriage is adapted to beadjusted in such a manner that the stroke of this switch which issmaller than the stroke of the guiding element may be carried out at anydesired location within the distance of the stroke of the guidingelement and that, if desired, it may also be adjusted so as to changethe length of its stroke.

The present invention therefore consists in the application of thesefive features and their combination and association with each other,whereby all of the requirements for properly guiding a metal strip willbe accomplished so that, for example, the strip may be guided along oneedge, for which purpose it is merely necessary to adjust the carriage onthe side opposite to this edge, or the strip may be guided so that itscentral axis always remains in a constant position by carrying out anadjustment of both carriages in opposite directions symmetrically to thecentral axis of the strip, while the pressure upon the edges of thestrip may be manually adjusted as desired at any time during the guidingoperation.

Another feature of the invention consists in the possibility ofconnecting auxiliary devices in a very simple manner to the adjustingmeans for the carriage for indicating or registering at any time orcontinuously the Width of the metal strip or for giving a signalwhenever the strip exceeds or is narrower than a certain desired Width.

The various features and advantages of the present invention will becomemore clearly apparent from the following detailed description thereofwhich is to be read with reference to the accompanying drawings ofwhich;

FIGURE 1 shows a longitudinal section of one of a pair of associatedslide carriages while,

FIGURE 2 shows the aforesaid pair of carriages and their associatedrelationship.

In the drawings, each guide element 1 is illustrated in this particularembodiment of the invention as consisting of a roller which is rotatablymounted in a bifurcated slide member 7 and adapted to engage upon one ofthe edges of the strip 8 which is to be guided. Slide member 7 isslidably guided in a socket of a housing or carriage 2. A coil spring 3and a cup spring 4 are mounted within this socket so that the slidemember 7 will be pressed with a relatively Weak pressure in thedirection of the arrow 19. As more particularly shown in FIGURE I slidemember 7 is capable of carrying out a stroke H, the end positions ofwhich are determined by the cup spring 4 when in the flattened conditionand the front end of a bushing 11 which is threaded in the bottom of thesocket and mounted on the shaftlike extension of slide member 7 so as tobe rotatable and axially slideable thereon. Bushing 11 is adjustable todifferent positions in its axial direction relative to carriage 1 andfrom the outside thereof by means of a shaft 9 with a square outer endand a pinion 10 on its inner end which engages with a set of gear teethon the threaded bushing 11. When shaft 9 is turned in one or the otherdirection, bushing 11 is screwed either toward or away from cup spring4, whereby the length of the stroke H of slide member 7 may beregulated. As shown, a nut for a selective abutment by bushing 11 isdisposed on the shaft-like extension of slide member 7 in normallyspaced relationship from the bushing to afford a variable clearanceI-I-x. The rear end of the shaftlike extension of slide member 7 carriesa pin 12 which acts upon a contact arm 13 of a limit switch 5 providedwith leads 18. The particular position where the limit switch 5 maycarry out its stroke may be varied by means of a setscrew 14. The twocarriages 2 which are associated with each other and may form one ofseveral pairs are connected with each other by means of a spindle 15with right and left-hand threads which is adapted to be driven in eitherdirection by an electric motor 6 through a reduction gear 16 so that, bymeans of a nut 17 which connects each carriage 2 with spindle 15, bothcarriages may be moved toward each other when the Width of strip 8decreases or away from each other when the width of the strip increases.The electric circuit of the two limit switches 5 of each pair ofassociated carriages 2 for operating the motor 6 is not illustrated inthe drawings as its design will be obvious to any person familiar withthe art.

The end 20 of spindle 15 may be connected to any desired auxiliarydevices, for example, to an indicating instrument which may also beprovided with a recording device and signal means for measuring andindicating the width of the metal strip. These auxiliary devices arealso not illustrated in the drawing since they may be of variousdesigns.

Of course, instead of carrying out the adjusting movements of the twocarriages 2 by means of a single motor and a spindle with right andleft-hand threads, it is also possible to connect the carriages to twoseparate spindles which are driven by separate motors. This may beadvisable, for example, if a very wide strip is to be guided along itsedges. These motors may then run synchronously with each other, and, ifdesired, it is also possible to operate only one motor to adjust theassociated carriage, while the other motor and carriage are standingstill.

The advantages which are attained according to the invention by beingable to guide a strip or the like very accurately without exerting anyundue pressure upon its edges are of very great importance in numerousoperations, for example, in edge-trirnming, shaping, pipe weld"- ing,punching, cold-rolling, etc.

Although my invention has been illustrated and described with referenceto the preferred embodiment thereof, I wish to have it understood thatit is in no way limited to the details of such embodiment, but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim is:

1. An apparatus for guiding a metal strip or the like of a changingwidth during its movement in its longitudinal direction between a pairof guiding means, each of said guiding means being mounted forlongitudinal movement in one of a pair of slide carriages, spring meansadapted to press said guiding means against one edge of said strip,means for adjusting the carriages of said pair of carriages relative toeach other; mutually facing cooperating means on each of said guidingmeans and on each respective carriage for limiting the length of thestroke of each guiding means within its slide carriage to a distanceconsiderably smaller than the distances traversed by said guiding meansdue to the changes in width of the strip as caused by normalmanufacturing tolerances, and switch means mounted within each carriage,comprising a movable switch arm, each of said guiding means comprising ashaft having means projecting axially from one end thereof forcontacting an end portion of said movable switch arm at one end of saidstroke to close said switch means.

2. An apparatus according to claim 1, wherein said means projectingaxially from said one end is constituted by a pin member.

3. An apparatus according to claim 1, wherein each of said guiding meanscomprises abutment means, each of said slide carriages comprising socketmeans, a spring abutting each of said abutment means and said socketmeans and yieldingly opposing said longitudinal move ment of saidguiding means in the direction of a respective one of said switch means.

4. An apparatus according to claim 3, further comprising means foradjusting the length of said stroke of each of said guiding means,including an abutment member on each of said slide carriages, each ofsaid socket means comprising a threaded bushing member adjustablythreaded on a respective one of said carriages, and a spring memberinterposed between a respective said abutment member and a respectivesaid threaded bushing member.

5. An apparatus according to claim 4, said spring member comprising acup spring abutting each said abutment member and an end of each saidthreaded bushing, the tension of each said cup spring being adjusted byadjust ing movement of a respective threaded bushing.

2 5 6 6. An apparatus according to claim 4, further com- ReferencesCited by the Examiner prising means for adjusting each said threadedbushing, UNITED STATES PATENTS 3: 1??? iqmpnslgg f tieth 2,317,4684/1943 Krieger 33 147 re e us mg an se ec rvey operae pinion mean 52,410,718 11/1946 Crawford 200 61 X engagmg Smd gear teeth- 2,552,4595/1951 Rice 200-61 '7. In an apparatus according to claim 1, each ofsaid 2,301,308 7/1957 cubeuis 200*61 switch means being provided withset screw means for varying the position of said switch means on arespective BERNARD GHHEANY Pnmm'y Exammer' carriage. NEIL C. READ,Examiner.

1. AN APPARATUS FOR GUIDING A METAL STRIP OR THE LIKE OF A CHANGINGWIDTH DURING ITS MOVEMENT IN ITS LONGITUDINAL DIRECTION BETWEEN A PAIROF GUIDING MEANS, EACH OF SAID GUIDING MEANS BEING MOUNTED FORLONGITUDINAL MOVEMENT IN ONE OF A PAIR OF SLIDE CARRIAGES, SPRING MEANSADAPTED TO PRESS SAID GUIDING MEANS AGAINST ONE EDGE OF SAID STRIP,MEANS FOR ADJUSTING THE CARRIAGES OF SAID PAIR OF CARRIAGES RELATIVE TOEACH OTHER; MUTUALLY FACING COOPERATING MEANS ON EACH OF SAID GUIDINGMEANS AND ON EACH RESPECTIVE CARRIAGE FOR LIMITING THE LENGTH OF THESTROKE OF EACH GUIDING MEANS WITHIN ITS SLIDE CARRIAGE TO A DISTANCECONSIDERABLY SMALLER THAN THE DISTANCES TRAVERSED BY SAID GUIDING MEANSDUE TO THE CHANGES IN WIDTH OF THE STRIP AS CAUSED BY NORMALMANUFACTURING TOLERANCES, AND SWITCH MEANS MOUNTED WITHIN EACH CARRIAGE,COMPRISING A MOVABLE SWITCH ARM, EACH OF SAID GUIDING MEANS COMPRISING ASHAFT HAVING MEANS PROJECTING AXIALLY FROM ONE END THEREOF FORCONTACTING AN END PORTION OF SAID MOVABLE SWITCH ARM AT ONE END OF SAIDSTROKE TO CLOSE SAID SWITCH MEANS.